Two heterogeneous photocatalysts have been prepared by entrapment of [nBu₄N]₄W₁₀O₃₂ in a silica matrix, through a sol–gel procedure: SiO₂/W30% and SiO₂/W10% with 30% and 10% of decatungstate, respectively. They are characterized by the presence of micropores of about 7 Å and 15 Å and mesopores of about 25 Å. Due to different preparation procedures, SiO₂/W10% presents a more remarkable porous network than SiO₂/W30%. The morphological features of SiO₂/W30% and SiO₂/W10% differ from those of their parent material SiO₂/W0%, indicating that incorporation of the decatungstate induces a significant modification of the porous texture of the siliceous material. These photocatalysts demonstrate good stability in the oxygen-assisted photooxidation of 1-pentanol and 3-pentanol, which have been chosen as models of primary and secondary aliphatic alcohols. In particular, photoexcitation (λ > 290 nm, 25 °C, 760 torr of O₂) leads to conversion of these two substrates to pentanal or 3-pentanone, with a mass balance of about 90%. There is a strong effect of the solid support on the reactivity of the two alcoholic substrates. In particular, oxidation of 1-pentanol with SiO₂/W10% is about four times faster than with [nBu₄N]₄W₁₀O₃₂ in homogeneous solution. Preferential adsorption phenomena, due to the hydrophilic character of silica explain the photocatalytic properties of the two heterogeneous systems, because adsorption favours the contact between the photoexcited decatungstate and the primary OH group of 1-pentanol. Moreover, some kind of shape selectivity, due to the microporous structure of the investigated materials, likely contributes to control the conversion yields.